Stripper for coaxial cables



Dec. 15, 1964 J, TOLMAN 3,161,088

STRIPPER FOR COAXIAL CABLES Filed Dec. 4, 1962 INVENTOR. HAROLD J. TOL MAN BY FULW|DER,- PATTON- RIEBER, LEE & UTECHT ATTORNEYS United States Patent 3,161,088 STRWPER FOR CUAXIAL QAIBLES Harold J. Tolman, 3357 La Boga, Long Beach, tCaiif.

Filed Dec. 4', I952, Ser. No. 242,187 V s (Ilairns. (or. sr-as) This invention relates generally to novel strippers for coaxial cables and particularly toimproved coaxial cable strippers for dressing the ends of such cables in a uniform and expeditious manner preparatory for connection to other components.

With the development of the electronics industry there has been a tremendous increase in the use of coaxial and shielded wire cables because of their advantages and even indispensibility in various types of circuitry. The dressing of the ends of such cables is a slow operation when atcoaxial cables and insulated conductors. a

A further object is to provide a device of this natur which is compact, readily portable and simple and cheap to manufacture.

Another object is to provide a coaxial cable stripper which will dress the ends of such cables in a uniform and expeditious manner, Without accidental damage to the insulation or conductive layers.

Other prime objects of my invention include: (1) to provide a novel hand tool for dressing coaxial cables which is easily carried in the pocket; (2) the provision of a device for this purpose wherein the danger of accidentally cutting the hands or clothes is practically eliminated.

Further objects and advantages of my invention will become apparent from the following description taken in 1 conjunction with the annexed drawings.

My invention resides in the concept of a coaxial cable stripper comprising a cutter housing having a bore forming a guideway for a coaxial cable, and a slot in the side of said cutter-housing communicating with said bore, a cutter-support means movable towards said bore and a plurality of cutters mounted on said cutter-support means with their cutting edges transverse to said bore in stepwise array in registration with andrnovable through said slot, whereby on rotating said housing around said coaxial cable Whilst urging said'cutter support means toward said bore the layers of the cable are severed by said cutters in step-Wise form.

Below is described and illustrated a preferred form of djlfidd Patented Dec. 15, 1964 16 with bore 29. Within the recess lies a clamp-lever 11 attached by a transverse pivot 12 over slot 16 to the clamp-housing for inward and outward swinging movement. Thepivoted end of clamp-lever 11 is formed as a' cam 14 which protrudes below the opening 16 only when the clamp-lever is positioned within recess 15. One end of the clamp-housing 10 has an internally threaded neck 31. I v

' Longitudinally adjacent to the clamp-housing Ill is a cutter-housing having a bore 29 in alignment with bore 19 forming a continuation of the guideway for the coaxial cable, and an out-turned shoulder 33 forming an annular groove 34. A split collar 3i) has an inturned shoulder 32 which is seated in annular groove 34, and an externed thread by means of which it is screwed into the threaded neck 31 of the clamp-housing 10, thus holding the cutter-housing 20 rotatably about its longitudinal axis in spaced alignment with clamp-housing It).

The cutter-housing 20 has a longitudinal recess 26 communicatingo'ver a portion of its length with the bore 2a through a slot 27. Within the recess 26 lies a cuttersupport lever 21 attached at one end by a transverse pivot 22 for inward and outward swinging movement. Three cutter blades 23, 24 and 25 each of successively greater depth and of width less than that of slot 27 are secured to the lever 21 with their cutting edges transverse to the bore 29 in spaced step-Wise array, so as to protrude through and below slot 27 when lever 21 is positioned within recess 26. 7

A second longitudinal aperture 28 opening into bore 29 provided in cutter-housing 20 facilitates positioning of the cable and inspection of the progress of the cutting operation.

The external surfaces of the clamp-housing and cutterhousings are knurled to provide firm grip on the device.

A coaxial cable of the normal type includes layers consisting of an inner conductor 41, consisting of a single wire or a plurality of wires, covered by an inner insulation 42 and an outer braided shield conductor 43, and an outer covering 44. i

The bore 19 and 29 of the stripper is of diameter sufficient to enable a coaxial cable of predetermined external diameter to be guided therethrough.. The depths to which the cutters 23, 2,4 and 25 protrude into the bore when lever 21 is in the closed position are respectively equal to the thickness of layer 44, the combined thickness of layers 43 and 44, and the combined thickness of layers 42, 43 and 44.

a coaxial cable stripper'in accordance with the invention.

In the drawings:

FIGURE 1 is a perspective view of the stripper cutting position;

FIGURE 2 is a detail longitudinal section taken on line 22 of FIGURE 1; a I

FIGURE 3 is a detail longitudinal section corresponding to that of FIGURE 2, but showing the stripper in the position for withdrawal of the stripped cable; and

FIGURE 4 is a detail transverse section'talren on line In operation the levers 11 and 2E are lifted to their open positions as illustrated in FIGURE 3 and the end of the cable 40 is inserted through the bores 19 and 29 until it is seen through aperture 28 to be the desired distance beyond the positions of the cutters when closed. Holding the cable in this position the lever 11 is closed thus clampingthe cable in place. The" lever 21 is then gradually closed at the same time rotating the cutterhousing .20 around the cable until the entire circumference of the cable has been cut to the successive depths of the layers at the respective cutter positions, when the lever 21 is fully closed. The lever 11 is then opened and the stripper pulled away from the cable whereby the cutters 23, 24 and 25 retain the severed portions of the stripped layers 44, 43 and 42, as shown in FIG- URE 3, and the end of the cable is left neatly dressed and ready for connection in the desired circuitry. To ready the stripper for re-use, the lever 21 is opened and the severed portions of. the stripped layers 44, 43 and 42 may be expelled through the bore 2? by means 'of a probe or similar device inserted through aperture 28. It will be appreciated that when the stripper is not being utilized the levers 11 and 21 are kept in closed position making the stripper compact and easily and safely carried in the pocket, if desired, by means of a spring clip such as is commonly used with pens, pencils, screw drivers, etc.

It will be obvious to those skilled in the art that the embodiment of this invention which has been described above may be subject to many modifications and changes. For example, other clamping devices such as a bench vice may be employed. Again the outer-support means need not be pivotally supported by the cutter-housing but may be supported by grooves or rods and springurged inwardly or outwardly as desired, an essential feature being that the cutters are urged concurrently in rotary fashion to the cable. FIGURE 4 shows an arcuateshaped cutter. However, a rectangular cutter or a rotatably mounted disc cutter may be used.

The terms and expressions employed are used as terms of description and not of limitation, and it is not in tended, in the use of such terms and expressions, to exclude any equivalents of the features shown and described or portions thereof. All such modifications as properly fall within the scope of equivalency of the following claims are therefore intended to be covered as being within the spirit of the invention.

I claim:

1. A coaxial cable stripper comprising: a cylindrical clamp and a cylindrical cutter-housing, each having a bore forming a guideway for said cable, said clamp comprising a cylindrical clamp-housing having a longitudinal recess terminating in an opening communicating with said bore, a clamp-arm pivoted in said opening having a cam at the pivoted end, said cam protruding into said bore only when said clamp-arm is positioned within said recess, a collar connecting said cutter-housing to said clamp rotatably about the common longitudinal axis, a longitudinal inspection aperture in the side of said cutter-housing communicating with said bore, a slot in the side of said cutter-housing communicating with said bore, a lever pivoted at one end of said cutter-housing so as to swing in the plane of said slot, a plurality of cutter blades mounted on said lever with their cutting edges transverse to said bore in step-wise array movable in unison in the plane of said slot into said bore, whereby on applying said stripper to said cable by means of said clamp so that the cable is positioned in said guideway, and rotating said housing around the cable simultaneously urging said lever toward said guideway, the layers of the cable are severed by said cutters and on release of said clamp and withdrawal of the cable the severed portions are stripped therefrom leaving the cable dressed in step-wise form.

2. A coaxial cable stripper according to claim 1 wherein said opening is adjacent to said collar, said lever is pivoted at the end of said cutter-housing remote from said collar, said cutter blades are three in number, whereof when said lever is in its fullest position of movement into said slot the cutting edges of the blades are, respectively, proximate to the outer surface of the inner conductor, the outer surface of the inner insulation and the outer surface of the shield conductor of the cable.

3. A coaxial cable stripper according to claim 1 wherein said cutter blades are arcuate.

References Cited in the file of this patent UNITED STATES PATENTS 893,132 Bork July 14, 1908 1,801,706 Westfall Apr. 21, 1931 2,120,398 Edwards et a1 June 14, 1938 2,317,944 Schaefer Apr. 27, 1943 FOREIGN PATENTS 460,344 Canada Oct. 18, 1949 529,066 Great Britain Nov. 13, 1940 

1. A COAXIAL CABLE STRIPPER COMPRISING: A CYLINDRICAL CLAMP AND A CYLINDRICAL CUTTER-HOUSING, EACH HAVING A BORE FORMING A GUIDEWAY FOR SAID CABLE, SAID CLAMP COMPRISING A CYLINDRICAL CLAMP-HOUSING HAVING A LONGITUDINAL RECESS TERMINATING IN AN OPENING COMMUNICATING WITH SAID BORE, A CLAMP-ARM PIVOTED IN SAID OPENING HAVING A CAM AT THE PIVOTED END, SAID CAM PROTRUDING INTO SAID BORE ONLY WHEN SAID CLAMP-ARM IS POSITIONED WITHIN SAID RECESS, A COLLAR CONNECTING SAID CUTTER-HOUSING TO SAID CLAMP ROTATABLY ABOUT THE COMMON LONGITUDINAL AXIS, A LONGITUDINAL INSPECTION APERTURE IN THE SIDE OF SAID CUTTER-HOUSING COMMUNICATING WITH SAID BORE, A SLOT IN THE SIDE OF SAID CUTTER-HOUSING COMMUNICATING WITH SAID BORE, A LEVER PIVOTED AT ONE END OF SAID CUTTER-HOUSING SO AS TO SWING IN THE PLANE OF SAID SLOT, A PLURALITY OF CUTTER BLADES MOUNTED ON SAID LEVER WITH THEIR CUTTING EDGES TRANSVERSE TO SAID BORE IN STEP-WISE ARRAY MOVABLE IN UNISON IN THE PLANE OF SAID SLOT INTO SAID BORE, WHEREBY ON APPLYING SAID STRIPPER TO SAID CABLE BY MEANS OF SAID CLAMP SO THAT THE CABLE IS POSITIONED IN SAID GUIDEWAY, AND ROTATING SAID HOUSING AROUND THE CABLE SIMULTANEOUSLY URGING SAID LEVER TOWARD SAID GUIDEWAY, THE LAYERS OF THE CABLE ARE SEVERED BY SAID CUTTERS AND ON RELEASE OF SAID CLAMP AND WITHDRAWAL OF THE CABLE THE SEVERED PORTIONS ARE STRIPPED THEREFROM LEAVING THE CABLE DRESSED IN STEP-WISE FORM. 